Comparison of transient overvoltage suppression capability of grid-forming converter and synchronous condenser

When faults such as blocking and commutation failure occur in a high-voltage direct current （HVDC） transmission system， they can cause transient voltage fluctuations near the sending-side converter station and lead to the disconnection with power grid. Firstly， the operating principles， response characteristics， and key parameter influences of the grid-forming energy storage open-loop control strategy are analyzed. Then， the reactive response characteristics of the synchronous condenser are analyzed， and a comparison is made between the grid-forming energy storage reactive power control model and the excitation regulation control model. Finally， a semi-physical simulation system is established， including EHVDC， photovoltaics， synchronous condenser， and grid-forming energy storage， to conduct comparative experiments on the effect of suppressing AC transient overvoltage under DC commutation failure. The results indicate that grid-forming energy storage and distributed synchronous condenser with the same capacity can achieve similar effects in terms of reactive transient response speed and the ability to suppress AC transient overvoltage.